weiskopf



Sept. 30, 1930. 0a WEISKOPF CALCULATING MACHINE Filed May 1, 1926 6 Sheets-Sheet Sept. 30, 1930. o. WEISKOPF CALCULATING MACHINE 6 Sheets-Sheet 3 vFiled May 1, 192

ln ven for. O/fo Weiskopf If/J' Sept. 30, 1930.

' O. WEISKOPF CALCULATING MACHINE Filed May 1, 1926 6 Sheets-Sheet 5 s P 1930. o. WEISKOPF 1,776,800

CALCULATING MACHINE Filed May 1, 1926 6 Sheets-Sheet 6 /n ven for:

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Patented Sept. 30, 1930 PATENT OFFICE or'ro wmsxorr, or nnrunnpnnmm CALCULATING MACHINE Application filed May 1, 1926, Serial No. 106,111, .and in Germany my 5, 1925..

My invention relates to computing attachments for typewriters. The attachment comprises a totalizer frame which is adapted to be displaced transversely to the machine and which is preferably independent of the platen carriage of the typewriting machine so that it can be set for, any desired column independently of the platen carriage.

The computing attachment may be used in connection with any standard typewriter and on which column addition and subtraca tabulator key is depressed, the platen ear riage of the typewriter. will jump to the first decimal of the number which is to be set and at the same time the totalizerframe and the crossfooter will also be set to this decade; When writing digits by means of the numeral keys of the typewriter, the driving wheels of the totalizer frame are automaticallv displaced to the right step by step for each sue cessive decade.

Ifit is desired to use the typewriter without operating the computing attachment, the operative connection between the typewriter and the attachment is cut out by a separate key or the like and the attachment is locked in itscut-out position 'so'that the parts of the.

attachment are not operated idly with the keys of'the. typewriter and the typewriter keys may be operated freely.

In the drawings afiixed to this specification and forming part thereof a computing attachment embodying my invention is illustions, respectively.

Fig. 2 is an end elevation of one of the push.

bars which operatively connect the numeral keys of the typewriter with the computing L attachment.

. Fig. 4 is a plan View, also diagrammatic, of the computing attachment.

Figs. 5 to 16 illustrate details ofthe machine on a larger scale.

Fig. 5 being a section on the line 55 in Fig. 10, while Fig. 5 is the continuation of Fig. 5 on the right hand side partly broken away.

Fig. 6 is a section on the line. 66 in Fig.

Fig. 6 being the continuation of Fig. 6 on the right hand side, partly in section on the-line 66 in Fig. 5.

Figs. 7, 8 and 9 are elevations partly in section on the line 55 in Fig. 10, showing various phases of the denominational setting function, r

Fig. 10 is a section on the line 10-1O in F ilg. 5,

"igs. 11 and 12 are an elevation and a plan view, respectively, showing the connection of the tabulator' keys of the typewriter with the decade slides, a

Fig. 13 is a section on the line 13-13 in Fig. 4,

Fi 13 is the continuation of Fig. 13 on the righthand'side,

Fig; 14 is a section on the line 1414 in Fig. 4,

Fig. 15 is a section at right angles to that in' Fig. 14,

Fig. 16 is a section on the line 1616 in Fig. 10,

Fig. 16 is the continuation of Fig. 16 on the righthand side.

The general arrangement of the computing I attachment will first be described briefly with reference to Figs. 1 to 4.

In these figures 1 is the casing of the attachment, 1 is a covering plate at its rear end,'on which are a typewriter T. he typewriter T is not shown in detail as its construction has no bearing on the present invention, only its rovided supports S for numeral key levers 2 and its tabulator key levers 10 being indicated in Figs. 1 and 3'.

A U-shaped frame is fulcrumed at 7'in the front end of the casing 1. The two parallel side arms 6 of the frame support a transverse bar 5 at the rear of the casing 1 and the connecting levers 4 for the computing attachment are fulcrumed on the bar 5. Push bars 3 secured to the connecting lever are provided with pockets 3 at the upper ends for the reception of the key levers 2, as shown in Fig. 2. A spring 8 which is suspended in the cover plate 1 and secured to one of the arms 6, tends to hold the frame in its upper position in which its arms 6 abut against checks 9 in the side plates of the frame 1'. In this position, as shown in Fig. l, the key levers 2 are engaged in the pockets 3. A key 6 provided on one of the arms 6 is adapted to depressthe frame against the action of the spring 8 so that the ends of the push bars 3 011 the connecting levers 1 are shifted out of reach of the key levers 2. The frame may be locked in this position by any suitable means (not shown). Each connecting lever 4 is pivoted to a vertical slide bar 11. The slide bars are guided in a bracket 12 which is arranged in an elevated compartment 1 at the front end of the frame 1, and each slide bar is provided with a pullback spring 13. The function of the slide bar will be described further below.

The compartment '1 is L-shaped in plan view as will appear from Fig. 4. A totalizer frame 57 for column calculations can be displaced transversely to the machine in the recess of the L-shaped compartment. A cross footer for performing line operations is ar ranged in the compartment 1 and controls 22* and 22 project from the cover plate of the compartment. The control 22 serves for setting the mechanism of the totalizer frame 57 for addition or subtraction, as indicated by the marks Add and Sub. The control 22 serves the same purpose for the crossfooter in the casing. The indications are visible through holes 60 in the cover plate of the totalizer frame 57 and 60 in the cover plate of the compartment 1. Digits are marked on the compartment at V for the totalizer frame 57 and at H for the crossfooter. Holes 61 arranged in line with the holes 60 are adapted to receive pins 62 for checking the motion of the totalizer frame 57 which is provided with a spring 63 (Fig. 13 tending to pull it to the left as far as permitted by a check which cooperates with the pins 62 and has a push button 54 by aid of which it can be released.

Referring now to Figs. 5 to 10, it will appear that upon depression of a key lever 2 the corresponding lever 4 will pull its slide bar 11 down into the position shown in dotted lines in Fig. 10 and in full lines in Fig. 8. A roller 11 supported in a shoulder at the rear face of the slide bar is adapted to cooperate with a slide 15 which is arranged below the roller 11. The slide 15 has extensions 15' and 15 at each end which are supported on rollers 14, and a pull-back spring 10 tendsto hold-a projection 17 engaged with a check 17 on the bracket 12. Grooves 16 are formed in the front face of the slide. Each groove is bordered by a vertical face 16 at the left and an inclined or cam face 16 at the right, the inclination of the latter faces increasing from the left to the right corresponding to the numerals 0 to 7 of the key levers 2 by which the slide bars 11 are pulled down. Then the roller 11 of one of the slide bars 11 enters one of the grooves, it engages the corresponding inclined face 16 and pushes the slide 15 to the right a distance corresponding to the numeral on the key lever which has been depressed. lVhen the roller 11 has arrived at the lower edge of the groove 16, it engages the left hand vertical face 16 of the groove, thereby checking further displacement of the slide 15 so that the slide can only move exactlythe distance which it had been displaced by the depression of the slide bar, and overrunning of the slide is prevented even with rapid operation of the machine.

The vertical position of the faces 1 6 also permits the slide bars to descend further after having pushed aside the faces 16" and to perform certain operations in connection with the denominational setting, as will be described further below. Gear wheels 20 and 20 are supported on pins 21, 21 in' an extension 12 of the bracket 12, as shown in Figs. 5 and 6 The gear wheel 20 is operatively connected with the mechanism in the totalizer frame 57, and the gear wheel 20 is operatively connected with the mechanism of the crossfooter in the compartment 1, by means which will presently be described. A support 18 is secured to or formed integral'with the righthand end of the slide 15 and the controls for setting the mechanism for addition, subtraction and idle are arranged in thi support. Two pairs of coupling pins 19, 19 and 19 19 are arranged to slide in the support 18 and springs 23 tend to force these pins into recesses 20 of two gear wheels 20, 20 which are free to rotate on pins 21 in the extension 12 of the bracket 12. The pins 19 and 19 are arranged below, the pins 19' and 19 are arranged above the axes of the gear wheels 20, 20. Therefore, when the slide 15 is moved in a given direction the wheels-20,

20 will be rotated in the same or in opposite directionaccording to which pin 19 has been permitted to engage one of the recesses 20. Rotation to the right corresponds. to addition, rotation to theleft corresponds to subtraction. When the pins are not engaged in one of the recesses, the gear wheels 20, 20 will remain stationary notwithstanding the motion of the slide 15. The recesses 20 are slotted as best seen in the wheel 20 (Fig.

5), so as to provide the necessary clearance for the parallel displacement of the slide 15 and the rotation of the wheels 20, 20. In Figs. 5, 5" and 6, 6" this arrangement is illustrated for the stationary cross footer at the right and the totalizer frame 57 at the left. If required, a second cross footer mi ht be provided.

he coupling pins 19 are adjusted separately for each counting mechanism by means of vertical cylinders 22, 22' which are provided with handles 22", 22 for rotation and are notched at24 for the lower pins 19 and .19 and at 24' for the upper pins 19' and 19", respectively. The notches 24 and 24 inthe two cylinders extend at an angle of 120 degs. with respect to each other. In the position of the cylinders illustrated in Fig. 6 the upper coupling pin 19' of the gear wheel :20 is allowed by the notch 24 of its cyli'nder22 to enter the recess 20 of the gear wheel 20 under the action of its spring 23 while the lower pin '19 is retained as it is not in register with a notch in the cylinder 22.- Similarly the notches of the cylinder 22 do not re 'ster with any of its pins 19" and 19 and t erefore both pins are retained. By rotating the cylinder 22 through 120 the upper couplin pin 19' will be arrested by the upper notcdm 24' and the lower pin 19 will be, released by the lower notch 24 so that it is free to enter the recess 20 of its gear wheel 20. On further rotation of the cylinder through 120 the lower pin 19 will be withdrawn from the notch in the gear wheel so that the gear wheel 20 is now completely disengagedfrom the slide 15. Consequently the totalizer and the crossfooter may be set separately so that for instance additlon may be performed on one of them and subtraction on the other, or the other may remain stationary, or the same operation may be performed on both.

The rotation of the gear wheel 20 is transferred to the driving shaft 58 of the totalizer frame 57 through the medium of a 'pinion' 25, bevel gearing 26, 27, a shaft 28, as shown in Fig. 16, a slot 28 in said shaft and a driving wheel 29 which is adapted to slide on said shaft, but is held against rotation by a key engaging the slot 28*. This wheel cooperates with pinions on the digit wheels 59 of the totalizer head, the indications of which are read in the holes Similarly the rotation of the gear wheel 20' is transmitted to the shaft 58 of the crossfooter through the medium of the parts 25, 26, 27, 28 .and 29'.- The wheel 29 operates the gear wheels of the digit wheels 59', the indications of which are read in equippedwith any desired number of digit wheels and pinions, as will appear from vided with ten holes 60 for the ten digit wheels 59' on the shaft 58'.

The denominational setting of the driving wheels 29 or 29' for the desired denomination is effected by the decade slides 30 and 30' as illustrated in Figs. 7, 8, 11 and 12. The denominational slides are rigidly connected by a rod 52 and are guided on two slide bars 31 extending below the wheels 29, 29 all over the width of the mechanism and secured in the side walls of the casing 1. The slide 30 is connected with the driving wheel 29 by a pin 30 (Fig. 7) which engages an annu ar groove 29 in the wheel 29 so that the wheel partakes in the motion of the slide 30. A spring 32 which is anchored in an arm 12" of the bracket 12 as shown in Fig. 7, tends to pull both slides to their final position at the right of the machine in which the wheels 29. 29' are in' register with the first digit of their respective counters.

A lever 34 (Figs. 11 and 12) secured on a stud 33 in the casing 1 below the tabulator keys 40 is adapted to beoperated by these keys. A sector 35 also secured on the stud 33 meshes with a pinion 36 on-a shaft 37 on which a pulley 38 for a cable or wire 39 is secured. This cable is connected with the denominational slide 30. Upon depression of a tabulator key 40 the pulley 38 will be rotated and will move the slide 30 to the left against the action of its spring 32, movin the slides and the wheels 29 and 29' into t e position corresponding to the first digit of the desired number.

As the stroke of the tabulator keys 40 is constant whereas the motion which'they impart to the denominational slide 30, 30, is a function of the position to be set, the leverage exerted by the several keys on the lever 34 varies. That tabulator key which sets the highest position is arranged in proximity to the shaft 33 so that the leverage of this tabulator key is much reduced as compared with the key cooperating with the end of the lever 34. The lost motion of the keys with respect to the lever 34 may be varied by adjustable conical sleeves on the lever 34. It will be understood that by displacing such sleeves to the right in Fig. 11, the lost motion will be reduced and, by displacing them to the left,

l on

it will be increased. Set screws, not shown,

' the rack. When the slide 30 is moved to the left by the cord 39, the pawl 41 is free to slide on the teeth but locks the slide against mo 'tion in the opposite direction. The slide will be unlocked on depression of oneof the keys 2, as, when the key moves downwards as indicated in dotted lines in Fig. 10, the corresponding slide bar 11 will strike the rack 45 and will move its teeth out of the way ofthe pawl 42, but will at the same time movethem into the path of :1 lug 30 of the slide 30 which extends at the rear of the pawl 41 and allows the slide 30 to move to the right under the action of its spring 32 only so far that both wheels 29 and 29 get disengaged from the pinions of the digit wheels which they had engaged. lVhen the key lever 2 which had been operated, is released, the spring 13 of the corresponding slide bar 11 moves its roller 11' out of the notch in the slide ff'which it had engaged, allowing the slide to return to its initial position and at the same time ro tating the driving wheel 29 back into its initial position. This rotation mustbe performed before the driving wheels become engaged with the pinions of the digit wheels 59, 59'. It is therefore necessary that the rack 45 should be retained in its depressed position until the driving wheels 29, 29 have per-' formed their backward rotation, .and only after this has been effected, the lug 30 of the slide 30 may be released, allowing the driving wheels to mesh with the pinions of the next decade on the right. This function is performed by a supplementary pawl 46 on the rack 45, which is fulcrumed on a pin 46 and is held applied against a check 48 by a pullback spring 47. The pawl cooperates with the slide and in the initial position of the slide it engages a shoulder 49 at the left of the recess 49 in the slide 15. When the slide "is moved to the right by one of the rollers 11 engaging with one of its cam faces 16*, the pawl is moved to the right so as n ot to interfere and, when the rack 45 is'depressed,.the

, pawl 46 moves out of the recess 49 altogether as shown in Fig. 8 and the spring 47 returns it into contact with the check 48. When the rack 45 is released by the slide bar 11; it can not return into its initial position as the pawl 46 abuts against the lower edge of the slide 15. Only when the slide 15 returns to its initial position, the pawl 46 enters the recess 49 under the action of the spring 45. At the same time the lug is released and the teeth are placed into the path of the pawl 41. The slide 30 now moves forward again untilathe pawl engages the adjacent tooth of the rack and the driving wheels 29, 29 mesh with the pinions of the digit wheels for the following decade. I

As the denominational slides 30, 30 are rigidly connected, it is not necessary to duplicate the locking means for the slide 30 with regard to the slide 30. i

'The column setting of the tota-lizer 59 is ellected by means of a pawl 53, as shown in Figs, 14 and 15. This pawl 53 is arranged at the lefthand plate of the casing 1 and is fulcrumed on a pin 53*. A push button 54 is arranged for movement in the cover plate 1 of the compartment l against the action of a pull-back spring 55 which tends to hold the pawl 53 engaged with a check 56. The

rear end of the lever 53 projects into the totalizer frame 57 and in this position the pawl projects into the path of the pins 62. 63 (Fig. 13) is the pull-back spring which, as mentioned in the introduction, pulls the totalizer frame to the left, when the pawl 53 is released by depressing the button 54. The totalizer frame is moved to the left until the next pin 62 engages the pawl 53 which has been released by its button 54.

The operation of the calculating mechanism will now be illustrated by three examples.

[Lamnpia'L-The simplest case is that in which the first subdivision of the totalizer frame is utilized. This first subdivision defines a columnin which additions or subtractions are performed, for instance when writing out accounts. The totalizer frame 57 is in its final position at the right, as shown in Fig. 4. Let us suppose that the following calculation is to be performed:

3475.25 698.92 mm 375.81 m

The handle 22 is set to Add, the tabulator key .40 for the numbe i' 1000 is depressed, the amount 3475.25 is typed on the typewriter by means'of the key levers 2 and will appear in the first six holes 60" opposite the sealeV. The platen carriage of the typewriter is now set for the next line and the tabulatorkey 100 is depressed, whereupon the next item 698.92 is typed and the result of the addition, viz. 4174.17 will appear in the holes 60. The key 6 (Figs. 1 and 3) is now depressed in order to shift the push bars 3 out of reach ofthe key levers 2 and the total 4174.17 is copied on the typewriter. Now the handle 22 is set on Sub, the tabulator key 100 is depressed and the amount to be subtracted (375.81) is typed. The result of the subtraction, the total 3798.36, will now appear in the holes 60. The tabulator key.1000 is now depressed, the push bars 3 are shifted by means of the key 6 and the total is copied on 1,77e,eoo

, the typewriter. The di 't wheels of the total- The total. 3798.36. may be kept in the crossfooter for the purpose of further calculations or it may be canceled at the same time as the indication of the totalizer 59 by setting the handle 22 to subtraction. Automatic cooperation of the crossfooter is important for. copying out and current accounts.

Example 2.In this case line additions and subtractions are performed in the subdivision of the totalizer 59 and at the same time in the crossfooter, that is, if the items to be added each item. Notwithstanding this the calculation is performed as in the first example. This mode of calculation is not possible with the combinations hitherto known of typewriters and calculating mechanisms because their totalizers are not independent of the platen carriages of the typewriters. I

In this examplethe total will appear in the first subdivision of the totalizer, but the calculation might have been performed in any subdivision of the totalizer. This also applies to the first example.

Example 3.In this case several subdivisions of the totalizer are used, for instance additions and subtractions are performed in four columns or subdivisions and at the same time the items in the horizontal rows are added or subtracted.

Let us suppose that the following calculation can be performed 365% Q. 36 1327. 48 1296.27 --20oo. 67

27. 19 -18. 95. 23a 50 348. (B -592. 91 1342. 56 -8Q. 82 468. 91 25356. 92 'm! -which has been written with suitable application of the respective-tabulator key, will appearin the first column of the totalizer and in the crossfooter. The button 54 is now I depressed so that the second column faces the graduation V; the handle 22 is set to said slide.

Sub. The item 28.36 appears in the second column of the totalizer 59 and the difference of the two items 365.28 and 28.36 ap are in the crossfooter. Now the button 54 is again operated so that the totalizer jumps to the third column. The handle 22 is returned to Add, the item 1327.48 is written out and will appear in the third column of the totalizer frame 57' while the crossfooter adds this item so thatthe amount 1664.40 will appearin its holes 60. Now the button 54 is depressed for the fourth column and the item 1296.27 is written. The total of the first horizontal row, 2960.6 7 appears in the holes 60". hehandle 22" is now set to Idle, the handle 22 is set to Sub, and the item is copied. In the same manner the other horizontal rows are written and calculated, the only consideration being that items which are to be subtracted must only be written when the handle 22* of the totalizer is set to Add and the handle of the crossfooter is set to Sub. When the third horizontal row has been completed, the items 17 35.03-933.63+

2022.98+27001.27 will appear in the several columns of the totalizer 57 The handle 22 is now set to Sub and the amounts which constitute the sums'of the two vertical columns are copied as described. At the same time they are added andsubtracted in the crossfooter where the total 29825.65 will appear in the holes 60 and this total is co ied out after the totalizer handle 22 has con set to Idle and the handle 22 of the crossfooter has been set to Sub. If it is not desired to find the sum of the horizontal row, thecrossfooter is set to Idle.

I wish it to be understood that I do not desire to be limited to the exact details of constructions shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. A computing attachment for typewriters comprising a totalizer frame adapted to be displaced laterally on said attachment, tabulator ke s on the typewriter, a denominational slide adapted to be displaced on said attachment, means connected with said tabulator keys for displacin said slide, a shaft extendm parallel to t c direction in which said sli e is displaced, means on said shaft for operating the totalizer head in said frame and operatrvely connected with said shaft, and a connection between said operating means and said slide adapted to cause said means to partake in the movement of 2. A computing attachment for typewriters comprisin a totalizer frame ada tedtO be displaced aterally on said attac ent,

'tabulator keys on the typewriter, a denominational slide adapted to displaced. on said attachment, a lever fulcrumed in said attachment and arranged below. said tabulator keys, an operative connection of said slide and said lever for displacing said slide, a shaft extending parallel to the direction in which said slide is displaced, means on said shaft for operating the totalizer head in said frame and operatively connected with said shaft, and a connection between said operating means and said slide adapted to cause said means to partake in the move ment of said slide.

3. A computing attachment for typewriters comprising a totalizer frame adapted to be displaced laterally on said attachment, tabulator keys on the typewriter, a denominational slide adapted to be displaced on said attachment, a lever fulcrumed in said attachment and arranged below said tabu lator keys, so as to move through various angles for the same stroke of any of said tabulator keys, an operative connection of said slide and said lever for displacing said slide, a shaft extending parallel to the direction in which said slide is displaced, means on said shaft for operating the totalizer head in said frame and operatively connected with said shaft, and a connection be tween said operating means and said slide adapted to cause said means to partake in the movement of said slide.

4. A computing attachment for typewriters comprising a totalizer frame adapted to be displaced laterally on said attach ment, tabulator keys on the typewriter, a denominational slide adapted to be displaced on said attachment, a lever fulcrumed in said attachment and arranged below said tabulator keys, adjustable means on said lever 'for varying the motion imparted 'to it by a. given stroke of said tabulatorkeys, an operative connection of said slide and said lever for displacing said slide, a shaft extending parallel to the direction in which said slide is displaced, means on said shaft for operating the totalizer head in said frame and operatively connected with said shaft, and a connection between said operatmg means and said slide adapted to cause said means to partake 'in the movement of said slide.

a. A computing attachment for typewrlters comprising a totalizer frame adapted to be displaced laterally on said attachment, tabulator keys on the typewriter, a

denominational slide adapted to be displaced.

on said attachment, a lever fulcrumed in said attachment and arranged below said tabulator keys, a sector secured on said lever, a shaft rotatabl carried in said mechanism, a pinion on said shaft adapted to mesh with said sector, a pulley on said shaft and a cord on said pulley connected with said slide, a shaft extending parallel to the direction in which said slide 1s dis laced, means on said last-mentioned shaft oroperating the totalizer head'in said frame and operatively connected with said shaft and a connection between said means and said slide by whlch said means are caused to partake in the motion of said slide.

6. A computing attachment for typewriters comprising a totalizer frame adapted to be displaced laterally on said attachment, a slide adapted to reciprocate in said attachment and operatively connected with the keys of the typewriter so that motion is imparted to said slide upon depresssion of the keys of the typewriter so that motion is imparted to said slide upon depression of the keys, a gear wheel rotatably carried in said mechanism and operatively connected with the totalizer head in said frame, means on said slide arranged on both sides of the axis of rotation of said gear wheelso as to impart thereto rotation in either direction, and means for alternately throwing in and out said connecting means.

8. A computing attachment for typewriters comprising a totalizer frame adapt ed to be displaced laterally on said attachment, tabulator keys. on the typewriter, a denominational slide adapted to be displaced on said attachment,.means connected with said tabulator keys for displacing said slide, a shaft extending-parallel to the direction in which said slide is displaced, means on said shaft for operating the totalizer head in said frame and operatively connected with said shaft, a connection between said means and said slide by which said means are caused to partake in the motion of said slide, a rack fulcrumed on said attachment, pawls on said slide adapted to cooperate with said rack, and means operatively connected with the keys of the typewriter for carrying said rack alternately into the path of one and of the other pawl.

9. A computing attachment for typewriters comprising a totalizer frame adapted to be displaced laterally on said attachment, tabulator keys on the typewriter, a. denominational slide adapted to be displaced on said attachment, means connected with said tabulator keys for displacing said slide, a shaft extending parallel to "'thc direction in which said slide is displaced, means onsaid shaft for operating the totalizer head in said frame and operatively connected with said shaft, a connection between said means and said slide by which said meansare caused to partake in the motion of said, slide, a rack fulcrumed on said attachment, a fixed pawl and a movable pawl on said slide, said movable pawl being adapted to be arrested by said rack only in one direction of motion of said slide, and means operatively connected with the keys of the typewriter for carrying said rack'alternately into the path of said fixed and said movable pawl.

10. A computing attachment for typewriters comprising a totalizer frame adapted to be displaced laterally on said attachment, a slide adapted to reciprocate in said attach ment and operatively connected with the keys of the typewriter so that motion is imparted to said slide upon depression of the keys, a denominational slide adapted to be displaced on said attachment, a shaft extending parallel to the direction in which said denominational slide is displaced, means on said shaft for operating the totalizer head in said frame and operatively connected with said shaft, a connection between said means and said slide by which said means are caused to partake in the motion of said slide, means connected with the tabulator keys of the typewriter for displacing said first-mentioned slide, a rack fulcrumed on said attachment. a fixed pawl and a movable pawl on said slide, said movable pawl being adapted to be arrested by said rack only in one direction of motion of said slide, automatic means for placing said rack into the path of said movable pawl, means controlled by the keys of the typewriter for placing said rack into the path of said fixed pawl, and a second pawl adaptedto cooperate with arecess on said first-mentioned slide so as to allow said rack to follow the action of said automatic means when said second pawl is able to enter said recess.

11. A computing attachment for typewritnection between said drives and said mechanism.

In testimony whereof I afiix my signature.

OTTO WEISKOPF.

ers comprising, a set of levers operatively connected with the keys of the typewriter, a slide bar operatively connected with each lever and adapted .to reciprocate in said attachment when said levers are operated by said keys, and a slide adapted to reciprocate in said attachment and having a cam face for each slide bar so that said slide is displaced transversely with respect to said slide bar, and having a vertical face opposite each earn face on which said slide bars are free to continue their motion when disengaged from the respective cam face.

12. A computing attachment for typewriters comprising a totali zer frame adapted to .be displaced laterally on said attachment, a

crossfooter on said attachment, a separate drive each for the totaliz'erhead in said frame and said crossfooter, a common mechanism operatively connected with the keys of the typewriter for operating said drive, a denominational slide for each drive, both slides being rigidly connected so as to move in unison, 

